Hi, I have had the pleasure of owning one of these from new!!!!
Last time I used it I could not get it to work until I replace one of the fuses inside. I suggest you check them first there are three from my recollecting. Surprisingly, having moved house and come to set it up again, Â I came on to the forum to ask the exact same question you raised….why does the sound keep cutting out. I have discovered that it has a feature:
“Automatic Power Handling Control which automatically turns down the volume when amplifier has been overloaded”
But sadly this is as far as I have progressed. I have tried 2 different sets of speakers with sound input generated from two different phones and a DAB radio but still have the same problem. Ill let you know if I find a solution